Last week, The New York State Department of Health and its Rockland County counterpart announced that for the time in nearly 10 years, the state had a confirmed case of polio—a life-threatening disease caused by the poliovirus that can cause serious neurological damage, including paralysis.
The infection was transmitted to a man in Rockland County from someone who had received the oral polio vaccine—a vaccine that was last administered in the US in 2000. According to The New York Times, officials said in a news release “that the virus may have originated outside the United States, where the oral vaccine is still administered.”
According to The Times, the infected man is from the Orthodox Jewish community in Rockland Country, which in 2018 and 2019, had a measles outbreak where more than 150 people contracted measles due to low vaccination rates.
The US has been free of polio since 1979 due to successful mass vaccination programs, but the poliovirus is very contagious and can still be contracted in other countries. Similar to this most recent case, the last case of polio in the US in 2013 was also brought into the country from abroad.
Though this polio infection likely poses a very low risk to people fully vaccinated against polio (according to the CDC, three doses are 99 percent to 100 percent effective), people who are unvaccinated or have not received all three doses should get vaccinated. To achieve herd immunity against polio, vaccination rates need to be relatively high at 80 percent fully vaccinated, according the WHO.